What fuel do you run in your EcoBoost pickup? (not HO)

I normally use regular 87 octane fuel, mainly the top tier from CostCo. Have used 93 in the past a number of times, and I can really tell the difference in power. Its rather immediate too. The engine senses the better gas, and adjusts the cam timers accordingly. Mine is a 2011, and the owners manual advises that 93 (or did it say 91?) is the preferred fuel. Mileage will increase slightly on 93, about 1 to 1.5 mpg. Its not enough to justify the 18-22% upcharge for 93.